Pyura discoveryi Herdman 1910

Pyura discoveryi (Herdman, 1910)

(Figures 29, 30)

Halocynthia discoveryi, Herdman, 1910:9. Pyura discovery Herdman 1912: 19. Primo & Vazquez 2007: 1804 and synonymy.

Stations (events when several trawling operations per station): 3-6(99)-6(103)- 8-10-11 (424)-11(429)-16A-26A- 27(33)-27(45)27(46)-30(66)-31-34-35-36(68)-41-42-45-47-49A-57-62-71-79-86E.

The largest specimen of the collection is 5.5 x 4 cm. The body has always the same triangular shape with well apart protruding siphons (Fig. 29 A) and a brown, hard, corrugated tunic. The basal part is often prolongated by threadlike extensions on fragmented substrate. The body wall is thin with regularly distributed muscles (Fig. 29 B). A velum is present inside both siphons. The oral tentacles are poorly ramified in 3 orders of size. The dorsal tubercle is complex located inside a wide V of the peritubercular area. The dorsal lamina is made of long languets. The most ventral of the 7 branchial folds is lower on the left side (Fig. 30 B). The branchial formula of a 35 mm specimen is:

E 1- 9 -4- 11 -5- 12 - 6- 16 -5- 20 -4- 16 -5- 12 -2-DL

DL- 3- 20 -3- 18 - 3- 20 -4- 20 - 3- 18 -3- 13 -3-8-1-E

Spiral stigmata can be seen at the top of the folds. The primary gut loop is widely open, the secondary curve is not obvious or absent (Fig. 30 A).The anus is lobed. The long gonads have numerous lobes (Fig. 30 A); the gonoducts are joined but become divergent at their extremity. No spinules could be detected on the siphon lining, even after a MEB examination.

One sequence for specimen S2 PYU 472a (BOLD: ASCAN044-10). No close hit in BOLD. This eurybathic species has a wide Antarctic distribution.